A surge in global gold prices has intensified illegal mining within Brazil's Amazon rainforest, accelerating deforestation in protected areas and raising mercury contamination to dangerous levels, according to officials and experts.
A study by Amazon Conservation and the Brazilian non-profit Instituto Socioambiental reveals that mining has driven extensive clear-cutting across three conservation zones in the Xingu region. The Terra do Meio Ecological Station recorded its first illegal mining in September 2024, with deforestation expanding to 30 hectares by the end of 2025. At the Altamira National Forest, illegal mining cleared 832 hectares between 2016 and September 2025, while a new mining front grew to 36 hectares by October 2025.
Satellite monitoring also detected a clandestine airstrip at the Nascentes da Serra do Cachimbo Biological Reserve, where illegal mining expanded from 2 hectares to 26.8 hectares in 2025. Amazon Conservation estimates that 80 per cent of mining-related deforestation in Brazil is likely illegal. Since 2018, about 496,000 hectares of rainforest have been cleared for mining across the Amazon, including 223,000 hectares in Brazil.
“What makes mining particularly problematic is that it targets protected areas and Indigenous territories,” said Matt Finer, director of Amazon Conservation’s Monitoring of the Andes Amazon program. Despite a 2023 crackdown in the Yanomami territory, localised enforcement has not curbed illegal mining. Federal prosecutor André Luiz Porreca described it as a “cat-and-mouse game,” noting that miners often return after officials leave. He said organised crime groups, including the Red Command and First Capital Command, finance these operations, with some dredges costing up to 15 million reais.
While enforcement eased pressure in Yanomami territory, illegal mining has intensified elsewhere, particularly across Indigenous lands in the Xingu River basin, where researchers warn the situation is most critical.
